Reducing nonradiative recombination in perovskite solar cells with a porous insulator contact

A analysis staff led by Prof. Xu Jixian from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) designed and normal a novel porous insulator contact (PIC) for perovskite solar cells. The PIC ameliorated the non-radiative cost recombination impact and the corresponding solar cell achieved an effectivity of as much as 25.5%. The examine was revealed in Science.

Conventional methods decreasing cost recombination at photocurrent transport interface are dominated by insertion of an ultrathin (~1 nm) passivation layer, which is a low-conductive materials between photo-absorbers and gap switch layers (HTLs). However, given {that a} slight improve within the thickness of passivation layer ends in drastic lower in photocurrent transport, a trade-off at all times exists between passivation and transport.

In this examine, researchers tried to interrupt this trade-off by introducing PIC into perovskite solar cells. PIC is a thick (~100 nm) dielectric layer with random nanoscale openings. Photocurrent transport was not sacrificed as a result of the present transported via the openings in PIC as a substitute of a tunneling impact. Further measurement additionally confirmed that the floor recombination velocity (SRV) was lowered by almost seven occasions, which demonstrated profitable passivation.

In addition, researchers investigated the origin of the superior efficiency of PIC. They found that the discount of recombination was a results of each lowered floor space and passivation impact. Surface wetting between PIC and perovskite layer was improved, which yielded larger perovskite crystallization high quality and thus longer bulk recombination lifetime.

This examine offers a brand new technique in decreasing cost recombination and bettering power conversion efficiency. Researchers additionally famous that with additional enchancment of PIC construction, the effectivity could possibly be even larger.